Chronometric signaling apparatus for telephone-lines



( No Model.) 2 SheetsSheet 1. H. D. SISSON.

' ChronometridSignaling Apparatus fpr Telephone Lines No. 238,977.Patented March 15,1881.

I IIIIIIIIIIIIIIIIIIIIIIIIII/ MH /V5555; K)

ATTORNEY (No Model.) v 2 Sheets-Sheet 2.

H. D. SISSON. Ghronometrin Signaling Apparatus for Telephone Lines.

No. 238,977. Patented March 15,1881.

ITNESSES: [NVEN TOR J? wzm. I I ATTORNEY N PETERS. PHOTO-LITHOGRAPHERWASHlNGTQN, u C,

UNITED STATES PATENT OFFICE.

HENRY D.

SISSON, OF MILL RIVER, MASSAUHUSETTS.

SPECIFICATION forming part of Letters Patent No. 238,977, dated March15, 1881.

Application filed July it, 1880. (No model.)

T 0 all whom it may concern:

Be it known that I, HENRY D. SIssoN, a citizen of the United States,residing at Mill River, in the county of Berkshire and State ofMassachusetts, have invented certain new and useful ImprovementsinOhronomctric Signaling Apparatus for Telephone-Lines, of which thefollowing is a specification.

My invention relates to-the signaling apparatus which is used inconnection with telephonelines when a number of different stations areconnected with the central or principal office by a single wire.

My invention consists in a method of and apparatus for bringing thesignaling apparatus at the several stations into the circuit of the mainline for a predetermined length of time, one after the other, insuccession, so that each station can send or receive signals to or fromthe central station only during the portion of time allotted to it.

It further consists in improved devices for keeping in unison thetime-trains by which the switches at the several stations arecontrolled, and in mechanism for preventing the alarm or signalingapparatus from being operated by the movements of the switches whenmoved by the time-trains.

In the accompanying drawings, Figure 1 is a diagram showing theconstruction and arran gement of the apparatus at one of the stations onthe line. Fig. 2 is a diagram showing the relative position of thecircuit-chan ing devices at the different stations on a single line.Fig. 3 is a diagram showing the appatatus by which the synchronism ofthe timetrains at the stations is effected and maintained. Fig. at is adetached view of the switch device, and Fi 5 shows certain details ofthe signaling or alarm apparatus.

Any desirable number of different stations may be placed upon a singleline; but in order to illustrate my improved system I have deemed itsufficient to describe and show its application to a line having foursubstations and one principal or central station, and to describe theapparatus at one sub-station, as the apparatus at all the othersub-stations is precisely similar, with the exception of the arrangementof the switches with reference to the circuits, which differs at eachsub-station,

as will be hereinafter more particularly explained.

I will now station.

Referring to Fig. 1, F represents a clock or time piece of ordinaryconstruction, except that its pendulum-bobfis of soft iron, preferablyof a cylindrical form. A stationary hollow coil of insulated wire, E, ismounted within the case of the clock in such a position that at eachoscillation the pendulum-bob swings partially into the opening in thecenter of the coil.

To one of the arbors of the time-train of the clock is attached ametallic arm, g, which revolves constantly at a uniform rate so long asthe time-train is in motion. I have shown this arm attached to theseconds-arbor of the clock, so that it will make one revolution perminute of time; but, if desirable, it may be attached to any otherportion of the train, so as to revolve at a greater or less speed thanthis, provided the other apparatus in the system is arranged in acorresponding manner.

Upon the face of the clock, underneath the arm g, is a circular dial ordisk, It, secured thereto by means of screws, or otherwise, so that itmay readily be removed, if necessary. This dial or disk II, (as bestseen in Fi 4) is composed of non-conducting material, such as wood orhard rubber, and has two concentric circles of metal let into its face.A segment, i, of the metallic circle i projects from the face of thedisk h, but the remaining portion is cut down flush with the surface ofthe disk. In like manner a segment, of the circle 70 projects, while theremainder is flush with the disk. The arm g, in its revolution, makes africtional contact with the projecting surfaces i and k, and these arearranged in the manner shown, with the projecting segments alternating,so that the arm y can be in contact with only one of them at a time,except during the instant itis passing from one to the other. Theproportion which the operative segments or contact surfaces of themetallic circles i and is of each disk bear to each other depends uponthe number of different sub-stations which are to be provided for. Inthe present system there are four such stations, and for describe theapparatus at a subthat reason the disk is so arranged that the arm g isin contact with the segment i during one-fourth of each revolution, andwith the segment during the remainder, or three-fourths of eachrevolution.

At each station is placed an alarm apparatus of any suitable character,actuated by an elec tro-magnct. I have shown in Fig. 1 an ordinarysingle-stroke electric bell, and a key for breaking and closing thecircuit for giving signals. I will remark, however, that the ordinarykey and sounder of the Morse telegraph may often be used as a signalingapparatus in connection with my invention with manifest advantage, bymerely substituting it in place of the keyand bell which I have shown inthe drawings.

The electrical connections at each sub-station are arranged as follows:The main line from the central station enters at 1, (see Fig. 1,) andthence goes by wire 2 to the hollow coil or helix E, and thence to therevolving arm or circuit-changer g. In the figure this arm isrepresented as being in a position to form a connection with the branchcircuit, which starts from the outer circle, '5, upon the disk h, andproceeds, by way of wires 4 and 5, to the signaling-key K, and thence bywire 6 to the electro-magnet M, which operates the alarm by causing thehammer a to strike the bell P. From the electro-magnet M the circuitreturns by way of the wires 7 and 8, and thence by wire 9, which is themain line, to the next sub-station in the series. The inner circle, 7a,of the disk or dial it is connected directly with the outgoing-line 9 bymeans of the wire 10. Thus it will be understood that if the time-trainof the clock F be set in motion the arm y will be caused to revolve at auniform rate of, say, one revolution per min-' ute, and during eachrevolution, or period of sixty seconds, the main line from the centralstation will be in connection with the branch line, which includes thekey K and signal-operatin g electro-magnet M, for fifteen seconds, whileduring the remaining forty-five seconds the connection will be madethrough the wire 10, cutting the signal devices entirely out of thecircuit. The arm g, therefore, forms a switch, which acts to direct thecircuit through the signal machinery for a predetermined length of timeand at given intervals, and directly through the main linefor theremainder of the time. There is a constant current maintained upon themain line by means of a battery at the central station, as hereinafterexplained, and this traverses the signal-operatin g magnet whenever thearm g closes the circuit through the branch in which itis placed. Thiscurrent is never interrupted by the operation of switching the circuitto and from the branch, the arm 9 being made broad enough so that itmakes contact with one segment before it breaks contact with the other.

In order to prevent the signal-bell P from being struck each time thatthe current is switched onto the branch, and made to traverse itselectro-magnet, and thus give a false 1 signal, I have devised themechanism shown in Figs. 1 and 5 of Sheet 1.

The armature-lever N carries a bell-hammer, n, upon a rod n. The rod 42passes through a slot, 1", formed in the guard 1', the latter being madeadjustable by means ofa screw, 0, which acts to clamp it between sideplates, 0, as seen in Figs. 1 and 5. Upon the slotted guard 1 an angulardog, if, is loosely placed, having a slot, t, at its angle, throughwhich passes the rod n of the bell-hammer. A projection is formed at sby filing away a notch or portion of the upper surface of the guard r,or otherwise, as shown.

The operation of this device is as follows: hen no current is passingthrough the electro-magnet M the bell-hammer and rod 11 remain in theposition indicated by the dotted lines, and the dog if in the positionindicated by the full lines, but a little farther to the left. If,now,the circuit is closed, the rod a is drawn forward, carrying the dogwith it; but the point of the latter strikes against the notch or projection s and stops the hammer, so that it can not strike the bell, andthe apparatus remains in this position until the circuit through themagnet is cut off. If, however, a signal is given by breaking andclosing the circuit by a key at the central station, or otherwise, thebell-hammer falls back, the rod it strikes the projection 16 on theupper end of the dog and tilts it backward into the position indicatedby the dottedlines, and then, upon the circuit being closed again, therod it moves forward so quickly that the dog does not have time to dropinto aposition to take hold of the notch or projection s, andconsequently the hammer n strikes the bell I and gives the requiredsignal. Thus it will be understood that unless the forward stroke of thebell-hammer is preceded by a back stroke the dog 6 cannot be thrown intoa position which will permit the bell to be rung.

In placin ga nu mberofclnonometricswitches at a like number of differentstations upon the line, they are arranged upon the principle shown inFig. 2, so that the time when the signal devices at any station areplaced in circuit and rendered operative is diiierent at eachsub-station. For example, the signal at station A maybe in circuitduring the first lifteen seconds of each minute, station E from thefifteenth to the thirtieth, station 0 from the thirtieth to theforty-fifth, and station D during the remainder of the minute. If theswitches are all so arranged as to revolve synchronously with a pointeror index placed upon the clock A at the central station, it is obviousthat the operator at that station may signal either of the sub-stationsduring the period of time appropriated to it, as indicated by the indexupon his own clock, without affecting any of the others, while they, inturn, may signal the central station in the same way.

In order to control the synchronisnl of the different time-trains andswitches in the system, I make use of the arrangement shown in IIS thediagram, Fig. 3, which consists of a standard-or controlling pendulum,a, at the central station. The pendulums of the time-trains at thesub-stations, one of which is shown at f, are adjusted so that theirnormal rate is as nearlyas possible the same as that of the standard.If, however, there should be any tendency to inaccuracy or departurefrom the rate of the standard pendulum, it is corrected by a deviceabout to be described.

The main line L, at the central station, passes normally through thebattery I), insulated spring 61, and metallic frame 0, and thence to theearth. A contact-screw, c, is inserted in the metallic rod of thependulum, which at each oscillation thereof momentarily touches thespring 61 and lifts it oif from c, breaking contact with the earth byway of L and forming a contact momentarily by way of wire L, whichincludes the supplementary battery 1). Thus an impulse from the latterbattery is superposed upon the normal current of the battery 12 upon theline at regular intervals corresponding with the vibrations of thestandard pendulum a, and these impulses pass through the coil E at eachsub-station. By this means, if the pendulum f, for example, should tendto vibrate too slowly, the impulse will be felt in the coil E before thecompletion of the vibration of f, and it will tend to accelerate itsmovement, and in like manner to check it on its return vibration, if itsrate of motion is too fast. These impulses are transmitted over the linewithout interrupting the circuit or interfering with its use forsignalingpurposes. It is not necessary in all cases to make use of thecontrolling device which has just been described, as in some cases therate of the timetrains may be sufficiently accurate for all practicalpurposes.

The switch 9 is mounted upon its arbor with a friction coupling, so thatit may be turned with a key, as the hands of a clock are turned, toadjust it in its proper position when necessary.

By making use of a removable disk or dial in the manner I have describedit is easy to adapt a system of switches to a greater or less number ofstations by simply removing the disks and replacing them with others,divided to correspond with the number of stations in the newarrangement.

The disk or dial may obviously be made in various forms withoutdeparting from the principle of the invention.

1 claim as my invention 1. The combination, substantially as herein setforth, of a main line, branch circuits located at different stationsupon said line, each of which branches includes an electro-magneticsignal oralarm apparatus, circuit-changers or switches at each station,so arranged as to transfer the circuit from the main line to the branch,or vice versa, without interrupting it, and synchronous time-trains,controlling the movements of the respective switches, so that the branchcircuits, which include the signaling device, are brought into the maincircuit one at a time, in regular succession and for a definite period.

2. The combination, substantially as herein set forth, of a main lineand two branch lines, an electromagnetic alarm or signal in one of saidbranch lines, a switch or circuit-changer, adapted to connect the mainline alternately with each of the two branch lines, and to form theconnection with either branch before breaking connection with the other,and a time-train to control the movements of said switch, and thusconnect the main line alternately with the respective branches for apredetermined length of time, substantially as specified.

3. The combination, substantially as hereinbefore setforth, of a mainline, branchcircuits located at different stations upon said line, eachof which branch circuits includes an electromagnetic signal or alarmapparatus, circuit-changers or switches at each station, so arranged asto transfer the circuit during predetermined intervals of time from themain line to the branch, or vice versa, time-trains controlling themovements of the respective switches, and a standard pendulum, arrangedto control the movements of the several timetrains by transmittingelectrical impulses through the said main line.

4. The combination, substantially as herein set forth, of a main line,branch circuits located at different stations upon said line,synchronously-revolvin g arms or circuit-changers at each station,controlled by time-trains, and removable dials at each station, havingcontact-surfaces electrically connected with the main and branchcircuits, respectively, and so arranged as to determine the portion oftime during which the electric current will traverse the branch line.

5. The combination, substantially as hereinbefore set forth, of anelectro-magnet, a

vibrating armature-lever, a notched guard, and

a movable dog, constructed and arranged, substantially as described, soas to drop into the notch of the guard and lock the armaturelever uponits forward movement, except when the latter is preceded by a backwardmovement.

Signed by me this 17th day of July, A. D. 1860.

HENRY D. SISSON. Witnesses:

FRANK L. Porn, MILLER O. EARLE.

IIO

